8 bit os_f handles
John Tytgat
John.Tytgat at aaug.net
Tue Mar 28 23:14:58 BST 2000
In message <200003282101.NAA29631 at purple.trimedia.sv.sc.philips.com>
"Jonathan Coxhead" <jonathan at doves.demon.co.uk> wrote:
> David wrote,
> | > I know that the point is to supply correct code. The only sense
> | > in which the code is "broken" at the moment is a sense that you
> | > have defined for yourself. That doesn't make it true!
> |
> | Sorry but it is the API, not a matter of my opinion.
>
> The A P I is 8-bit. That's true---at the OSLib level, and at the
> FileSwitch level as well (as we go to press ...).
That's not true. With all respect Jonathan, but the documented API talks
about filehandles returned in a 32 bit word (register). So a filehandle is
32 bit wide. The fact that it just returns values betwee 1 - 255 is just
a coincidence.
I do *not* care how FileSwitch is internally managing its filehandles as
as a programmer I have to make abstraction from it. I just want to make
sure that my programs linked today will work in the future when there
are >255 value filehandles (potentionally it is just being done by a
simple module which hijacks the OS_Find/OS_GBPB/... vectors).
> If the FileSwitch interface becomes 32-bit, the OSlib interface
> will evolve to keep pace.
...and in the meanwhile all programs linked with today's OSLib
potentionally won't run anymore. Great.
> The fact that the OSLib interface is 8-bit looks like a mistake.
> If only I could remember exaclt why I did it, I'd know for sure. :-(
Everybody makes mistakes. Let's move forward and try to correct these.
> [...]
> | Do any of the users in this mailing list have any code which will
> | break if os_f is redesigned as a 32 bit, and the application
> | recompiled? Its easy to tryout by just modifying the os.h header.
>
> This doesn't matter one bit. Hundreds of copies of OSLib have gone
> out, and I have no idea who's using them. Neither does anyone else.
> Even if the answer was "none", I'd still argue for compatibility:
> it's a professional ideal.
It also gives a professional touch when your programs keep on running
on a new OS without having to sputter "hold on, I need to recompile"
and send out hundreds update copies...
Let's add a big warning to the next OSLib version : using this version
requires a full recompile and note that filehandles (os_f) are now 32 bit
wide instead of 8 bit.
John.
--
John Tytgat, in his comfy chair at home BASS
John.Tytgat at aaug.net ARM powered, RISC OS driven
More information about the oslib-user
mailing list